728 MICROSCOPIC FORMS OF ANIMAL LIFE PROTOZOA 



itself, together with foreign organisms (ft, c) such as marine diatoms, 

 radiolarians, and infusoria which, having been entrapped in the 

 pseudopodial network, are carried by the protoplasmic stream into 

 the central mass, where the nutrient matter of their bodies is extracted, 

 the hard skeletons being cast out. Neither nucleus nor contractile 

 vesicle is to be discerned, but numerous floating and inconstant vacu- 

 oles (a) are dispersed through the substance of the body. After a time 

 the currents become slower ; the ramified extensions are gradually 



FIG. 567. Protonujxa aurantiaca: A, encysted statospore; B, inci- 

 pient formation of swarm-spores, shown at C escaping from the cyst, 

 at D swimming freely by their flagellate appendages, and at E creep- 

 ing in the amoeboid condition; F, fully developed reticulate organism, 

 showing numerous vacuoles, a, and captured prey, b, c. 



drawn inwards ; and, after ejecting any indigestible particles it m;iy 

 still include, the body takes the form of an orange-red sphere round 

 which a cyst soon forms itself, as shown in A. After a period of 

 quiescence the protoplasmic substance retreats from the interior of 

 the cyst, and breaks up into a number of small spheres (.B), which, at 

 first inactive, soon begin to move within the cyst, and change their 

 shape to that of a pear with the small end drawn out to a point. 

 The cyst then bursts, and the red pear-shaped bodies issue forth 

 into the water (C), moving freely about by the vibrations otflagetta 



